[Thymolipoma associated with myasthenia gravis].

A 42-year-old woman was admitted to our hospital complaining of left ptosis, diplopia, and muscle weakness. A diagnosis of myasthenia gravis was made. Chest roentgenograms, computed tomography (CT), and magnetic resonance imaging (MRI) showed a large anterior mediastial mass and suggested thymolipoma. Extended thymectomy was performed via a median sternotomy. Histopathological examination revealed that the tumor consisted of mature adipose tissue and weighed 1,500 grams, in which thymic tissues with Hassall' s corpuscles but without a germinal center were contained. The histological appearance was compatible with a typical thymolipoma. This is the 24th reported case of thymolipoma associated with myasthenia gravis.